Southwest Pet Policy 2026: $125 Pet Fare, Carrier Size, Rules

Southwest takes small, vaccinated cats and dogs in the cabin on domestic flights for a Pet Fare of $125 per pet carrier, each way. It doesn’t carry pets in the cargo hold, on international flights, or to and from Hawaii.

Last checked against Southwest’s own pages on 1 October 2026: its pet policy, pet carriers, destination rules, optional travel charges and service dog pages. The Pet Fare can change at any time, so confirm with Southwest before you book.

Southwest pet policy at a glance

Rule	What Southwest says
Pet Fare	$125 per pet carrier each way on US mainland flights; $35 between Hawaiian Islands
Which animals	Small, vaccinated domestic cats and dogs
Where	In the cabin, on domestic flights only
Minimum age	8 weeks
Carrier, maximum size	18 x 10.5 x 10 inches (Southwest’s own carrier is 15 x 10 x 10 inches)
Pets per carrier	Up to two small cats or two small dogs (same species)
Carriers per person	One per ticketed customer
Cargo	No pets in the cargo compartment
Not allowed	Flights to or from Hawaii; international flights, or any trip that includes one

Can my dog fly in the cabin on Southwest?

Yes, on domestic flights, if your dog is small, vaccinated, at least 8 weeks old, and fits in a carrier under the seat in front of you. Your dog, head and tail included, must be completely inside the carrier and able to stand up and move around easily.

Space is limited, so Southwest recommends reserving in advance by calling. Unaccompanied minors can’t travel with a pet.

Can birds fly on Southwest?

No. Southwest only accepts small, vaccinated domestic cats and dogs as pets in the cabin, and it doesn’t carry any pets in the cargo compartment.

How much is the Southwest Pet Fare?

$125 per pet carrier, each way, on US mainland flights, and $35 per carrier between Hawaiian Islands. You pay at the Southwest ticket counter at the airport, with an accepted credit card. If you cancel your reservation, the Pet Fare is refundable. Pets don’t earn Rapid Rewards points.

Southwest also sells its own pet carrier at the ticket counter, for $58.

Carrier rules

One pet carrier per ticketed customer. Each carrier can hold up to two small cats or two small dogs, not one of each.
The carrier must be made as a pet carrier, leak-proof and well ventilated, and fit under the seat in front of you.
Maximum size: 18 inches long, 10.5 inches wide and 10 inches high. The Southwest Airlines Pet Carrier is 15 x 10 x 10 inches.
Southwest recommends a soft-sided carrier, because under-seat space varies by seat. Aisle seats can have less room.
The carrier counts as either your personal item or your carry-on. You can board with a carrier and a personal item, or a carrier and a regular carry-on bag.
Pet strollers can be checked; standard checked bag fees apply.

Where pets can’t fly

Hawaii: pets aren’t allowed on flights to or from Hawaii. They are accepted on flights between Hawaiian Islands.
International: pets aren’t allowed on international flights, or on any itinerary that includes one.
Puerto Rico: specific requirements may apply. Check before you book.

At the airport

Pay the Pet Fare at the ticket counter.
At security you carry your pet through the screening device while the carrier is X-rayed.
Your pet stays in the carrier, head and tail inside, in the gate area, during boarding and for the whole flight.
Every airport Southwest serves has a pet relief area, but Southwest won’t hold a flight while you use it.
Board with your assigned boarding group.

On the plane

The carrier goes under the seat in front of you. A pet can never occupy a passenger seat.
You can’t sit in an exit row or the first (bulkhead) row with a pet.
A pet that scratches, whines or barks excessively, growls, bites, lunges, or relieves itself in the cabin or gate area can be refused boarding.

Southwest notes that animals with heart disease, anxiety disorders or flat-faced (brachycephalic) airways are more at risk of complications when flying, and that you and your vet are the best judges of whether your pet can travel safely.

Can a large dog fly on Southwest?

No. Southwest doesn’t carry pets in the cargo compartment, so a dog that doesn’t fit in an under-seat carrier can’t fly as a pet. Trained service dogs are a separate case (below).

Service dogs on Southwest

Southwest welcomes fully trained service dogs. Dogs are the only service animals it accepts.
Service animals in training, emotional support animals and therapy animals may travel as pets under the pet policy.
Bring a completed US Department of Transportation Service Animal Air Transportation form, digital or printed, to the ticket counter or gate on the day. It must be dated on or after the day you bought your ticket. A vest, ID card or registration certificate isn’t accepted instead.
The dog must be harnessed, leashed or tethered at all times, trained to behave, and under your control.
You can sit anywhere except an emergency exit seat. The dog sits at your feet, or on your lap if it’s no larger than a child under two. It can’t block the aisle or take a seat.
If you need a bulkhead or another specific seat because of your service dog, call Southwest after booking, at least 24 hours before departure.
Rules for service dogs vary for Hawaii, Puerto Rico and international destinations. Check the requirements for everywhere on your trip.

Quick answers

How much does Southwest charge for a dog?

$125 per pet carrier each way on US mainland flights, paid at the ticket counter.

Does Southwest allow birds?

No. Only small cats and dogs can travel as pets on Southwest.

What size pet carrier does Southwest allow?

Up to 18 x 10.5 x 10 inches. It has to fit under the seat in front of you.

Can I fly to Hawaii with my dog on Southwest?

No. Pets aren’t allowed on Southwest flights to or from Hawaii, only on flights between the islands.

Can two dogs share a carrier on Southwest?

Yes, two small dogs can share one carrier if they both fit and can move around easily.